Gasoline particulate filters with high initial filtering efficiency and methods of making same

ABSTRACT

Gasoline Direct Injection (GDI) engines require gasoline particulate filters (GPFs) as a key component of the emissions control system to reduce particulate emissions. GPFs are known to have poor initial performance, with performance increasing after the filter develops a cake. This poor initial performance make it impossible to accurately assess vehicle emissions performance at the mileage requirements for vehicle certification. Compositions and methods are disclosed to improve filtration efficiency in a fresh or low mileage GPF.

TECHNICAL FIELD

The disclosure relates to gasoline particulate filters employed in theexhaust systems of gasoline direct injection engines.

BACKGROUND

While conventional port fuel injection (PFI) gasoline engines haveextremely low particulate emissions, newer gasoline direct injection(GDI) engines have higher particulate emissions comparable to dieselengines. Gasoline particulate filters (GPF) have been introduced to theautomotive market for the exhaust systems of GDI engines to reduceparticulate emissions. Unfortunately, fresh, newly installed GPF haverelatively low initial filtration efficiencies.

The low filtration efficiency for a fresh or low-mileage GPF resultsfrom the need to establish cake filtration in the GPF as particulatematter removed from the exhaust stream builds up on the filtersubstrate. The transition from bed filtration to cake filtration isrelied on to achieve high filtration performance with minimum backpressure and filter size. Once cake filtration is achieved, the filterwill continue to work with very little change to filtration efficiencythroughout the service life of the unit.

In automobiles, this transition must be achieved rapidly to meetcertification testing requirements for particulate emissions. Due to thelimited operating time available to automakers to condition cars aheadof certification testing (on the order of hundreds to thousands ofkilometers, depending on the test), the accumulation of sufficientparticles to establish cake filtration via normal vehicle operation isdifficult to achieve during the certification testing window. Engineerscurrently design the filter to compensate for poor initial efficiency bysizing up the filter, increasing the porosity, modifying the pore sizedistribution, and other changes that improve initial filtrationefficiency. These design-arounds create a host of new problems,including cost, packaging constraints, and challenges to effectivelydistributing the exhaust stream across the filter. Therefore, methodsfor rapidly achieving high filtration efficiency are needed to permitmore efficient filter design and to meet certification testing limits.

SUMMARY

Based on the problems as set forth above, there is a need to rapidlyestablish cake filtration, which is not achievable by normal vehicleoperation, in order to accurately assess vehicle emissions forcertification and achieve low mileage compliance. Further, there is aneed for automakers to optimize filter designs for lifetime performancein the absence of these initial performance constraints. The presentdisclosure relates to high initial efficiency particulate filters thathave been pretreated to achieve cake filtration before or shortly afterinstallation in the exhaust system.

In one aspect, the particulate filter is a newly manufactured,pre-service gasoline particulate filter comprising pores, wherein thepores are at least partially filled with a particulate substance. Insome examples, the pre-service gasoline particulate filter provides afiltration efficiency of at least 80% after 100 initial miles. In someexamples, the particulate substance comprises at least one of a sootsurrogate substance, an ash surrogate substance, and an aggregateparticulate substance. In some examples, the particulate substancecomprises one or more of silica powder, alumina powder, talc, gypsum,soot, ash, flours, starches, and salts. In some examples, theparticulate substance is present on the gasoline particulate filter inan amount of at least about 0.5 gram/L. In other examples, theparticulate substance is present on the gasoline particulate filter inan amount up to about 6 grams/L. In some examples, the particulatesubstance comprises a plurality of particles, wherein each particle hasa diameter from about 10 nanometers to about 200 micrometers. In someexamples, the particulate substance comprises one or more of a surrogatesoot substance, a surrogate ash substance, and an aggregate surrogatesubstance.

In another aspect, methods of pretreating a gasoline particulate filtercomprise contacting the gasoline particulate filter comprising poreswith a particulate substance prior to installing the gasolineparticulate filter in a vehicle to produce a pre-treated gasolineparticulate filter, wherein the pores are at least partially filled withthe particulate substance. In some examples, the particulate substancecomprises one or more of a surrogate soot substance, a surrogate ashsubstance, and an aggregate surrogate substance. In some examples, theparticulate substance comprises one or more of silica powder, aluminapowder, talc, gypsum, soot, ash, flours, starches, and salts. In someexamples, the particulate substance comprises a plurality of particles,wherein each particle has a diameter from about 10 nanometers to about200 micrometers. In some examples, the contacting is via pneumaticconveyance of the particulate substance into the gasoline particulatefilter. In some examples, the pre-treated gasoline particulate filterproduced by the method is operable to provide a filtration efficiency ofgreater than 80% after 1000 initial miles.

In another aspect still, methods of increasing the initial in-servicefiltration efficiency of a gasoline particulate filter comprisecontacting a newly installed gasoline particulate filter with an exhauststream comprising particulate matter derived from a priming composition.In some examples, the priming composition may comprise a fuel additivecomposition. In some examples, the priming composition may be added tothe fuel used for the initial tank fill(s). Alternatively, the primingcomposition may be placed directly in the fuel tank prior to adding thefuel. In some examples, the priming composition comprises anorganometallic compound comprising manganese. In cases where the primingcomposition is added to fuel, the organometallic compound is present inthe priming composition in an amount effective to provide about 2 toabout 36 milligrams of manganese per liter of priming composition. Insome examples, the organometallic compound is methylcyclopentadienylmanganese tricarbonyl (MMT).

In yet another aspect, methods of increasing an initial in-servicefiltration efficiency of a gasoline particulate filter comprisecontacting a gasoline particulate filter with an exhaust streamcomprising particulate matter derived from a priming composition. Insome examples, the priming composition comprises a lubricantformulation. Because migration of a lubricant formulation into the fuelis limited, the lubricant formulation may be added to the fuel for theinitial tank fill or the first few tank fills. Alternatively, thelubricant formulation may be placed directly in the fuel tank prior toadding the fuel. In some examples, the priming composition comprises atleast one compound containing a chemical element selected from the groupconsisting of Ca, Mg, Mo, Zn, P, Ti, Mn, W, Na, and K. In some examples,the priming composition further comprises a fuel. In some examples, thepriming composition comprises a lubricant formulation in an amount of nomore than 3 wt. % based on the weight of the priming composition. Insome examples, the lubricant formulation comprises a sulfated ash value(SASH) of at least 3%, as measured by ASTM D874 (2018).

In some examples, the method further comprises measuring a filtrationefficiency of the gasoline particulate filter contacted with the primingcomposition, wherein the filtration efficiency is greater than 80% after100 initial miles. In other examples, the filtration efficiency isgreater than 80% after 100 initial miles. In some examples, the methodfurther comprises treating a fuel tank with the priming compositionduring original equipment manufacturing, and adding a fuel to the fueltank.

The following definitions of terms are provided in order to clarify themeanings of certain terms as used herein.

The terms “oil composition,” “lubrication composition,” “lubricating oilcomposition,” “lubricating oil,” “lubricant composition,” “lubricatingcomposition,” “fully formulated lubricant composition,” “lubricant,”“crankcase oil,” “crankcase lubricant,” “engine oil,” “enginelubricant,” “motor oil,” and “motor lubricant” are consideredsynonymous, fully interchangeable terminology referring to the finishedlubrication product comprising a major amount of a base oil plus a minoramount of an additive composition.

As used herein, the terms “additives”, “additive package,” “additiveconcentrate,” “additive composition,” “engine oil additive package,”“engine oil additive concentrate,” “crankcase additive package,”“crankcase additive concentrate,” “motor oil additive package,” “motoroil concentrate,” are considered synonymous, fully interchangeableterminology referring the portion of the lubricating oil compositionexcluding the major amount of base oil stock mixture. The additivepackage may or may not include the viscosity index improver or pourpoint depressant.

As used herein, the term “percent by weight”, unless expressly statedotherwise, means the percentage the recited component represents to theweight of the entire composition.

The terms “soluble,” “oil-soluble,” or “dispersible” used herein may,but does not necessarily, indicate that the compounds or additives aresoluble, dissolvable, miscible, or capable of being suspended in the oilin all proportions. The foregoing terms do mean, however, that they are,for instance, soluble, suspendable, dissolvable, or stably dispersiblein oil to an extent sufficient to exert their intended effect in theenvironment in which the oil is employed. Moreover, the additionalincorporation of other additives may also permit incorporation of higherlevels of a particular additive, if desired.

The term “TBN” as employed herein is used to denote the Total BaseNumber in mg KOH/g as measured by the method of ASTM D2896 or ASTM D4739or DIN 51639-1.

The term “alkyl” as employed herein refers to straight, branched,cyclic, and/or substituted saturated chain moieties of from about 1 toabout 100 carbon atoms.

The term “alkenyl” as employed herein refers to straight, branched,cyclic, and/or substituted unsaturated chain moieties of from about 3 toabout 10 carbon atoms.

The term “aryl” as employed herein refers to single and multi-ringaromatic compounds that may include alkyl, alkenyl, alkylaryl, amino,hydroxyl, alkoxy, halo substituents, and/or heteroatoms including, butnot limited to, nitrogen, oxygen, and sulfur.

Additional details and advantages of the disclosure will be set forth inpart in the description which follows, and/or may be learned by practiceof the disclosure. The details and advantages of the disclosure may berealized and attained by means of the elements and combinationsparticularly pointed out in the appended claims. It is to be understoodthat both the foregoing general description and the following detaileddescription are exemplary and explanatory only and are not restrictiveof the disclosure, as claimed.

LISTING OF THE FIGURES

FIG. 1 is a graph of time vs. filtration efficiency for a comparativeGPF and a GPF treated by the methods described herein.

DETAILED DESCRIPTION

The adoption of gasoline direct injection (GDI) technology is currentlydriven by the European Union (EU) climate change policy. About 40% ofnew non-diesel passenger car registrations in the EU in 2015 were GDIs.While GDIs are fuel efficient, thus reducing carbon dioxide emissions,fine particle emissions may be higher than the current Euro 6C limit of6×10¹¹ particles per kilometer under real driving conditions, accordingto a 2017 publication by the Association for Emissions Control byCatalyst (AECC) entitled “Gasoline Particulate Filter (GPF): How can theGPF cut emissions of ultrafine particles from gasoline engines”(hereafter “AECC 2017 publication”), which is herein incorporated byreference. GPFs are effective for reducing particulate emissions onceoperating in cake filtration mode after a soot cake has developed in thefilter. GPFs may optionally be coated with a three-way catalyst (TWC).The present disclosure relates to both uncoated and coated GPFs.

As described briefly above, a significant problem with GDI technology isthat newly installed gasoline particulate filters (GPFs) have a lowfiltration efficiency when operating in bed filtration mode prior tosufficient particle build-up in the pores of the GPF to permit operationin cake filtration mode. Fresh GPF filtration efficiency can be as lowas 30%. This low initial filtration efficiency will affect the emissionperformance during the certification to low mileage compliance. GPFscurrently must be designed with pore sizes optimized for sufficientlyhigh filtration before a soot cake is developed in the filter. Thus, theinstant disclosure advantageously allows for greater choices in designcriteria such as pore size by providing good initial filtration whilealso permitting certification testing that is reflective of GPF lifetimeperformance.

The GPF filter mechanism has two primary filtration modes: bedfiltration and cake filtration. At the early stage of GPF use, particleswill be trapped first in the pores of the GPF in a process called bedfiltration. This stage of filtration is characterized by relatively lowfiltration efficiency and rapid increase in back pressure. As particlescontinue to enter the GPF, the filtration media pores are filled withparticulate matter to produce a filtration cake, leading to a transitionfrom bed filtration mode to cake filtration mode once the particlesdeposit along the channel wall. Cake filtration will remain efficientuntil the filter reaches the threshold where the accumulated cake leadsto significant backpressure rise due to channel blockage. However, thisthreshold is reached when the accumulated cake is sufficient to clog thefilter, which usually occurs beyond the design service life for thefilter.

Particulate emissions consist of soot particles and ash particles, whichcan aggregate to form larger aggregate particles. GDI engines needemission control technologies to meet the regulatory requirements forreduced particulate emission. Under normal operating conditions, theaccumulation rate of soot is much faster than the accumulation of ashfor GPFs. For GDI vehicles, the cake accumulation rate is much slowerthan that of diesel. Thus, GDI vehicles require extended operating timeand/or mileage before the GPF reaches cake filtration mode in which thefiltration efficiency can be high enough to reduce the particulateemissions to compliant levels.

Primary soot and ash particles typically have a diameter of less than 10nm. The aggregate particles can have an average primary particlediameter of from about 7 nm to about 60 nm. Primary particles mayassociates to form aggregates that can have a diameter exceeding 200 nm,according to the AECC 2017 publication.

For GPF usage, a significant challenge is improving the early filtrationefficiency within low initial mileage, such as 100 initial miles, 250initial miles, 500 initial miles, 1,000 initial miles, 2,000 initialmiles, 3,000 initial miles, 4,000 initial miles, 5,000 initial miles,6,000 initial miles, 7,000 initial miles, 8,000 initial miles, 9,000initial miles, or 10,000 initial miles. Initial miles refers to thefirst miles of operation of an engine after a GPF is installed in theengine's exhaust system, and may correspond to the mileage specified forcertification testing. Filtration performance may be measured by roadtest or by bench test. In some examples where the testing is benchtesting, the filtration efficiency may be measured after an engineoperating time.

Compositions and methods are provided to rapidly achieve cake filtrationby introducing dopants to intentionally create a cake in a shorterperiod of engine operation than is possible by conventional engineoperation alone. A first solution provided herein is to treat the GPFexternal to the vehicle engine and exhaust system prior to installation,using compositions and methods that will establish the necessary cakeproperties. Treating the GPF external to the vehicle can be accomplishedduring the production of the GPF prior to fitting it to the vehicle, sothat a pretreated filter could be provided by an original equipmentmanufacturer (OEM). The treatment includes adding a particulatesubstance comprising particles to the GPF. A second solution providedherein is to add an additive to the fuel system during a period ofinitial operation. These fuel additives will produce combustion productscomprising soot and/or ash during initial GDI engine operation at a ratesufficient to rapidly achieve cake filtration in the GPF.

Pretreated Gasoline Particulate Filters

Pretreated gasoline particulate filters are disclosed. The pretreatedGPF includes a pre-service gasoline particulate filter comprising pores,with the pores at least partially filled with a particulate substance inan amount sufficient to achieve cake filtration upon pretreated GPFinstallation in the vehicle. “Pre-service filter” refers to a filterthat has been manufactured, but has not yet been installed in a vehicle.In some examples, the GPF pores are at least partially filled with aparticulate substance. In some examples, the GPF pores are at leastfifty percent (50%) filled by volume with a particulate substance. Inother examples, the pores are at least 10%, at least 20%, at least 30%,at least 40%, at least 60%, at least 70%, at least 80%, at least 90%, atleast 95%, at least 97%, at least 98%, or at least 99% filled by volumewith a particulate substance.

The addition of the dopant to a GPF to form a pretreated GPF will causean increase in GPF weight as compared to a non-doped GPF of the sametype. In some cases, the pretreated GPF weight is increased by at least0.01%, by at least 0.02%, by at least 0.03%. In some examples, thepretreated GPF weight is increased by up to 3%, by up to 1.5%, by up tomost 2%, by up to 1.5%, by up to 1%, by up to 0.5%, by up to 0.1%, or byup to 0.05% compared to the GPF prior to treatment. For example, if anuntreated filter weighs 1000 grams prior to treatment and weighs 1010grams after treatment, the GPF weight has increased by 1%.

In some examples, the particulate substance includes an inorganic ashsurrogate substance and/or a soot surrogate substance. Any particulatesubstance that can partition into the filter pores may be used as aninorganic ash surrogate substance and/or a soot surrogate substance.Thus, the diameter of the particles of the particulate substance must beequal to or smaller than the pore size of the filter. In some examples,the particulate substance is an organic compound. In other examples, theparticulate substance is an inorganic compound. In some examples, theparticulate substance is a metal oxide. In some examples, theparticulate substance includes one or more of silica powder, aluminapowder, talc, gypsum, soot, ash, flours, starches, and salts. A personof ordinary skill will understand that any particulate substancecomprising particles and/or particulate aggregates that areappropriately sized to the pores of the GPF may be utilized.

In some examples, the particulate substance is present on the gasolineparticulate filter in an amount of at least about 0.5 grams per liter(g/L) of filtration substrate. The filter internal volume is the volumeof space inside the filter housing that is occupied by the filtrationsubstrate. In some examples, the particulate substance is present on thegasoline particulate filter in an amount up to about 6 grams/L. In someexamples, the particulate substance is present on the gasolineparticulate filter in an amount from about 0.5 g/L to about 6 g/L, fromabout 0.75 g/L to about 5.5 g/L, from about 1 g/L to about 5 g/L, fromabout 0.5 g/L to about 3 g/L, or from about 3 g/L to about 6 g/L.

In some examples, the particulate substance includes a plurality ofparticles, wherein each particle of the plurality of particles has adiameter from about 0.01 micrometers to about 200 micrometers. In otherexamples, each particle in the plurality of particles has a diameterfrom about 0.05 micrometers to about 95 micrometers, from about 0.10micrometers to about 90 micrometers, from about 0.15 micrometers toabout 85 micrometers, or from about 0.20 micrometers to about 80micrometers. In some examples, at least 99% of the particles in theplurality of particles have an average diameter as specified herein. Inother examples, at least 98%, at least 97%, at least 96%, or at least95% of the particles in the plurality of particles have an averagediameter as specified herein. In some examples, no more than 5% of theparticles have an average diameter of greater than 200 micrometers. Insome examples, no more than 5% of the particles have an average diameterof less than 0.01 micrometers.

The particle size distribution of the surrogate substance may becontrolled to achieve cake filtration with a minimal amount ofparticulate substance. In some cases, the particle size distribution isfrom 1.1 to 2.0 (e.g., from 1.2 to 1.9, from 1.3 to 1.8, or from 1.4 to1.7). In other cases, the particle size distribution is 1.2, 1.3, 1.4,1.5, 1.6, 1.7, 1.8, 1.9, or 2.0.

In some examples, the particulate substance includes a plurality ofparticles having a bimodal distribution of particle diameters. Forexample, a soot surrogate substance may have a smaller average diameter,and an ash surrogate substance may have a larger average diameter. Insome examples, the plurality of particles includes particles having afirst average diameter and particles having a second average diameter.In some examples, the first average diameter is from about 0.25micrometers to about 2.5 micrometers. In other examples, the firstaverage diameter is from about 0.30 micrometers to about 2.3micrometers, from about 0.35 micrometers to about 2.0 micrometers, fromabout 0.40 micrometers to about 1.8 micrometers, from about 0.45micrometers to about 1.5 micrometers, or from about 0.50 micrometers toabout 1.0 micrometers. In some examples, the second average diameter isfrom about 2.5 micrometers to about 10 micrometers. In other examples,the second average diameter is from about 2.8 micrometers to about 9micrometers, from about 2.5 micrometers to about 8 micrometers, fromabout 3.0 micrometers to about 7 micrometers, from about 3.5 micrometersto about 6 micrometers, or from about 4 micrometers to about 5micrometers.

Filtration efficiency is calculated by measuring the count of particlesof greater than or equal to a particle diameter at the filter inlet andthe filter outlet, and expressing the number of particles exiting thefilter divided by the number of particles entering the filter, expressedas a percentage, during certain testing conditions. Testing conditionscan include on road testing, laboratory testing over driving cycle,engine steady state testing. In some examples, particles have a diameterof greater than or equal to 23 nanometers, 10 nanometers, or 5nanometers are counted. For example, if 1000 particles of per second aremeasured at the filter inlet and 400 particles per second are measuredat the filter outlet, the filtration efficiency is(1000-400)/1000×100=60%. In some instances, filtration efficiency of apretreated GPF installed in a newly manufactured vehicle may be measuredafter two hours of GDI engine operating time. The engine may be operatedwithin a vehicle in a road test, or may be operated external to avehicle in a bench test. In some examples, the gasoline particulatefilter provides a filtration efficiency of greater than 80% after twohours of GDI engine time. In other examples, the gasoline particulatefilter provides a filtration efficiency of greater than 75%, greaterthan 85%, greater than 90%, greater than 91%, greater than 92%, greaterthan 93%, greater than 94%, greater than 95%, greater than 96%, greaterthan 97%, greater than 98%, or greater than 99% after two hours of GDIengine time. In some cases, the engine is operated according to aStandard Cycle Test.

Alternately, filtration efficiency may be measured after a certainnumber of initial miles. In some examples, the gasoline particulatefilter provides a filtration efficiency of greater than 80% at 1000initial miles. In some examples, the pretreated GPF provides afiltration efficiency of greater than 80% at 100 initial miles, at 250initial miles, at 500 initial miles, at 750 initial miles, at 800initial miles, at 900 initial miles, at 1,000 initial miles, at 2,000initial miles, at 3,000 initial miles, at 4,000 initial miles, at 5,000initial miles, at 6,000 initial miles, at 7,000 initial miles, at 8,000initial miles, at 9,000 initial miles, or at 10,000 initial miles. Inother examples, gasoline particulate filter provides a filtrationefficiency of greater than 75%, greater than 85%, greater than 90%,greater than 91%, greater than 92%, greater than 93%, greater than 94%,greater than 95%, greater than 96%, greater than 97%, greater than 98%,or greater than 99% at 1000 initial miles. In other examples, gasolineparticulate filter provides a filtration efficiency of greater than 75%,greater than 85%, greater than 90%, greater than 91%, greater than 92%,greater than 93%, greater than 94%, greater than 95%, greater than 96%,greater than 97%, greater than 98%, or greater than 99% at 100 initialmiles.

Pre-Installation Methods of Treating Gasoline Particulate Filters

Methods of pretreating gasoline particulate filters are also disclosedherein. In some examples, the methods include contacting a gasolineparticulate filter including pores with a particulate substance prior toinstalling the gasoline particulate filter in a vehicle to produce apretreated gasoline particulate filter. In some examples, the pores areat least fifty percent (50%) filled by volume with a particulatesubstance. In other examples, the pores are at least 10%, at least 20%,at least 30%, at least 40%, at least 60%, at least 70%, at least 80%, atleast 90%, at least 95%, at least 97%, at least 98%, or at least 99%filled by volume with a particulate substance. The addition of thedopant to a GPF to form a pretreated GPF will cause an increase in GPFweight as compared to a non-doped GPF of the same type. In some cases,the pretreated GPF weight is increased by at least 0.01%, by at least0.02%, by at least 0.03%. In some examples, the pretreated GPF weight isincreased by up to 3%, by up to 1.5%, by up to most 2%, by up to 1.5%,by up to 1%, by up to 0.5%, by up to 0.1%, or by up to 0.05% compared tothe GPF prior to treatment.

The particulate substance may include any of the materials listed aboveand may have any of the particle sizes and particle size distributionslisted above.

In some instances, filtration efficiency of a pretreated GPF installedin a newly manufactured vehicle may be measured after two hours of GDIengine time. In some examples, the gasoline particulate filter providesa filtration efficiency of greater than 80% after two hours of GDIengine time. In other examples, the gasoline particulate filter providesa filtration efficiency of greater than 75%, greater than 85%, greaterthan 90%, greater than 91%, greater than 92%, greater than 93%, greaterthan 94%, greater than 95%, greater than 96%, greater than 97%, greaterthan 98%, or greater than 99%, after two hours of GDI engine time.

Alternately, filtration efficiency may be measured after a certainnumber of initial miles. In some examples, the gasoline particulatefilter provides a filtration efficiency of greater than 80% at 1000initial miles. In some examples, the pretreated GPF provides afiltration efficiency of greater than 80% at 100 initial miles, at 250initial miles, at 500 initial miles, at 750 initial miles, at 800initial miles, at 900 initial miles, at 1,000 initial miles, at 2,000initial miles, at 3,000 initial miles, at 4,000 initial miles, at 5,000initial miles, at 6,000 initial miles, at 7,000 initial miles, at 8,000initial miles, at 9,000 initial miles, or at 10,000 initial miles. Inother examples, gasoline particulate filter provides a filtrationefficiency of greater than 75%, greater than 85%, greater than 90%,greater than 91%, greater than 92%, greater than 93%, greater than 94%,greater than 95%, greater than 96%, greater than 97%, greater than 98%,or greater than 99% at 1000 initial miles. In other examples, gasolineparticulate filter provides a filtration efficiency of greater than 75%,greater than 85%, greater than 90%, greater than 91%, greater than 92%,greater than 93%, greater than 94%, greater than 95%, greater than 96%,greater than 97%, greater than 98%, or greater than 99% at 100 initialmiles.

In some cases, the particulate substance may be deployed to the pores ofthe GPF via a pneumatic conveyance, although other methods of insertionsuch as carrying the particulate substance into the pores by flow of afluid such as a gas (such as air, nitrogen, carbon dioxide, or argon) oran organic solvent will be apparent to those skilled in the art.Numerous powder particulate substances could achieve this goal withnon-limiting examples including silica powder, alumina powder, talc,gypsum, soot, flour, or corn starch with a particle diameter of between10 micrometers and 200 micrometers. While a wide variety of particlesizes are available commercially, the powders could be milled orclassified to obtain the desired particle size and particle sizedistribution.

Post-Installation Methods of Treating Gasoline Particulate Filters

A. Fuel Additives as Dopants

Additional methods of increasing the initial in-service filtrationefficiency of a gasoline particulate filter (GPF) are disclosed herein.These methods increase the cake accumulation rate through in-situexposure of the GPF to an exhaust stream including the combustionproducts of a fuel that is doped which particulate-producing substances.Using a priming composition in the fuel will result in production ofparticulate material that will rapidly build a cake. Thus, a “primingcomposition” includes a substance capable of producing particulatesubstance upon combustion.

In some examples, a fuel additive is used neat as the primingcomposition. A person of ordinary skill will understand that anyadditive that contributes to soot or ash production may be used.

One particularly appealing application is to place one or more fueland/or lubricant additives of the present invention in the fuel tank asthe first tank of fuel during in vehicle construction (i.e., factoryfluid fill). The additive may be delivered neat or at a highconcentration in a carrier, and is dissolved in fuel once fuel is addedto the fuel tank. This factory-fill fluid conditions the GPF foremissions within the first tank fill(s) of fuel enabling optimumemissions to be quickly established. Alternately, the additive is addedto the fuel used for the first or first few tank fills, such as thefirst one, two, three, four, or five tank fills. The filtrationefficiency of a GPF installed in a newly manufactured vehicle andexposed to particulate matter produced by the priming composition can bequantified by initial miles and/or engine time, as described above, andcan have any of the values described above.

In some examples, the methods employ a conventional fuel additive thatis soluble in fuel, such as an organometallic compound, that cangenerate ash during the combustion process to accumulate ash in the GPFfiltration substrate. The additive may be neutral to the combustionprocess, soluble in base oil and/or fuel, and compatible with the TWCsystem. One example of such a compound is an organometallic compoundsuch as methylcyclopentadienyl manganese tricarbonyl (MMT). Optionally,to ensure correct balance of chemistry in the combustion products,additional fuel components may be added. These compounds include variousfuel soluble phosphorous or sulfur compounds. Based on the need forapproximately 0.4 grams of ash per liter of internal filter volume toachieve 80% filtration efficiency, an MMT treat rate of about 8.3 mg Mnper liter of fuel (mg Mn/L) in several fuel tanks would be sufficientfor pretreating a particulate filter. MMT would serve the additionalbenefit of enhancing the octane in the vehicle during initial mileage,thus improving vehicle performance. In some examples, MMT is present inthe fuel in an amount from about 2 mg Mn/L to about 36 mg Mn/L (e.g.,from about 4 mg Mn/L to about 32 mg Mn/L, from about 4 mg Mn/L to about30 mg Mn/L, from about 6 mg Mn/L to about 26 mg Mn/L, from about 6 mgMn/L to about 20 mg Mn/L, from about 2 mg Mn/L to about 16 mg Mn/L, orfrom about 16 mg Mn/L to about 32 mg Mn/L.

In general, the additives are not completely combusted during engineoperation, and thus at least a portion of the additives will pass intothe exhaust system to provide particulate matter to the GPF. In somecases, the additives may be partially combusted before passing into theexhaust system. In some cases, the non-combustible additive may includean organometallic compound. In some examples, the organometalliccompound is selected from the group consisting of methylcyclopentadienylmanganese tricarbonyl (MMT) and ferrocene. In some examples, theorganometallic compound is methylcyclopentadienyl manganese tricarbonyl.

In some examples, the organometallic compound contains manganese and ispresent in the priming composition in an amount effective to provideabout 2 to about 36 milligrams of manganese per liter of primingcomposition. In other examples the organometallic compound is present inthe priming composition in an amount effective to provide about 4 toabout 30 milligrams, about 5 to about 25 milligrams, about 2 to about 20milligrams, or about 20 to about 36 milligrams of manganese per liter ofpriming composition.

In some cases, the priming composition further includes a fuel suitablefor the engine in the vehicle in which the filter will be installed. Incases where the priming composition further includes a fuel, any fuel orfuel compositions that is suitable for the engine may be used.

Hydrocarbon Fuel: The base fuels used in formulating the fuelcompositions of the present disclosure include any base fuels suitablefor use in the operation of gasoline engines configured to combust fuelat the high fuel pressures discussed herein. Suitable fuels includeleaded or unleaded motor gasolines, and so-called reformulated gasolineswhich typically contain both hydrocarbons of the gasoline boiling rangeand fuel-soluble oxygenated blending agents (“oxygenates”), such asalcohols, ethers and other suitable oxygen-containing organic compounds.Preferably, the fuel is a mixture of hydrocarbons boiling in thegasoline boiling range. This fuel may consist of straight chain orbranch chain paraffins, cycloparaffins, olefins, aromatic hydrocarbonsor any mixture of these. The gasoline can be derived from straight runnaptha, polymer gasoline, natural gasoline or from catalyticallyreformed stocks boiling in the range from about 80° to about 450° F. Theoctane level of the gasoline is not critical and any conventionalgasoline may be employed in the practice of this invention.

Oxygenates suitable for use in the present disclosure include methanol,ethanol, isopropanol, t-butanol, mixed C1 to C5 alcohols, methyltertiary butyl ether, tertiary amyl methyl ether, ethyl tertiary butylether and mixed ethers. Oxygenates, when used, will normally be presentin the base fuel in an amount below about 30% by volume, and preferablyin an amount that provides an oxygen content in the overall fuel in therange of about 0.5 to about 5 percent by volume.

Detergents:

Additional fuel additives may be employed. For example, suchsupplemental additives may include dispersants/detergents, antioxidants,carrier fluids, metal deactivators, dyes, markers, corrosion inhibitors,biocides, antistatic additives, drag reducing agents, demulsifiers,emulsifiers, dehazers, anti-icing additives, antiknock additives,anti-valve-seat recession additives, lubricity additives, surfactants,combustion improvers, and mixtures thereof.

A suitable additional additive may be a Mannich base detergent such as aseparate intake valve deposit (IVD) control additive including a Mannichbase detergent. Suitable Mannich base detergents for use in the fuelcompositions herein include the reaction products of a high molecularweight alkyl-substituted hydroxyaromatic compound, aldehydes and amines.If used, the fuel composition may include about 45 to about 1000 ppm ofa Mannich base detergent as a separate IVD control additive.

In one approach, the high molecular weight alkyl substituents on thebenzene ring of the hydroxyaromatic compound may be derived from apolyolefin having a number average molecular weight (Mn) from about 500to about 3000, preferably from about 700 to about 2100, as determined bygel permeation chromatography (GPC) using polystyrene as reference. Thepolyolefin may also have a polydispersity (weight average molecularweight/number average molecular weight) of about 1 to about 4 (in otherinstances, about 1 to about 2) as determined by GPC using polystyrene asreference.

The alkylation of the hydroxyaromatic compound is typically performed inthe presence of an alkylating catalyst at a temperature in the range ofabout 0 to about 200° C., preferably 0 to 100° C. Acidic catalysts aregenerally used to promote Friedel-Crafts alkylation. Typical catalystsused in commercial production include sulphuric acid, BF₃, aluminumphenoxide, methanesulphonic acid, cationic exchange resin, acidic claysand modified zeolites.

Polyolefins suitable for forming the high molecular weightalkyl-substituted hydroxyaromatic compounds include polypropylene,polybutenes, polyisobutylene, copolymers of butylene and/or butylene andpropylene, copolymers of butylene and/or isobutylene and/or propylene,and one or more mono-olefinic comonomers copolymerizable therewith(e.g., ethylene, 1-pentene, 1-hexene, 1-octene, 1-decene, etc.) wherethe copolymer molecule contains at least 50% by weight, of butyleneand/or isobutylene and/or propylene units. The comonomers polymerizedwith propylene or such butenes may be aliphatic and can also containnon-aliphatic groups, e.g., styrene, o-methylstyrene, p-methylstyrene,divinyl benzene and the like. Thus in any case the resulting polymersand copolymers used in forming the high molecular weightalkyl-substituted hydroxyaromatic compounds are substantially aliphatichydrocarbon polymers.

The term “polybutylene” is used herein in a generic sense to includepolymers made from “pure” or “substantially pure” 1-butene or isobutene,and polymers made from mixtures of two or all three of 1-butene,2-butene and isobutene. Commercial grades of such polymers may alsocontain insignificant amounts of other olefins. So-called highreactivity polyisobutenes having relatively high proportions of polymermolecules having a terminal vinylidene group are also suitable for usein forming the long chain alkylated phenol reactant. Suitablehigh-reactivity polyisobutenes include those polyisobutenes thatcomprise at least about 20% of the more reactive methylvinylideneisomer, preferably at least 50% and more preferably at least 70%.Suitable polyisobutenes include those prepared using BF₃ catalysts. Thepreparation of such polyisobutenes in which the methylvinylidene isomercomprises a high percentage of the total composition is described inU.S. Pat. Nos. 4,152,499 and 4,605,808, which are both incorporatedherein by reference.

The Mannich detergent may be made from a high molecular weightalkylphenol or alkylcresol. However, other phenolic compounds may beused including high molecular weight alkyl-substituted derivatives ofresorcinol, hydroquinone, catechol, hydroxydiphenyl, benzylphenol,phenethylphenol, naphthol, tolylnaphthol, among others. Preferred forthe preparation of the Mannich detergents are the polyalkylphenol andpolyalkylcresol reactants, e.g., polypropylphenol, polybutylphenol,polypropylcresol and polybutylcresol, wherein the alkyl group has anumber average molecular weight of about 500 to about 2100 as measuredby GPC using polystyrene as reference, or as another example the alkylgroup is a polybutyl group derived from polyisobutylene having a numberaverage molecular weight in the range of about 700 to about 1300 asmeasured by GPC using polystyrene as reference.

One suitable configuration of the high molecular weightalkyl-substituted hydroxyaromatic compound is that of a para-substitutedmono-alkylphenol or a para-substituted mono-alkyl ortho-cresol. However,any hydroxyaromatic compound readily reactive in the Mannichcondensation reaction may be employed. Thus, Mannich products made fromhydroxyaromatic compounds having only one ring alkyl substituent, or twoor more ring alkyl substituents are suitable for use in this invention.The long chain alkyl substituents may contain some residualunsaturation, but in general, are substantially saturated alkyl groups.

Representative amine reactants include, but are not limited to, alkylenepolyamines having at least one suitably reactive primary or secondaryamino group in the molecule. Other substituents such as hydroxyl, cyano,amido, etc., can be present in the polyamine. In an embodiment, thealkylene polyamine is a polyethylene polyamine. Suitable alkylenepolyamine reactants include ethylenediamine, diethylenetriamine,triethylenetetramine, tetraethylenepentamine and mixtures of such amineshaving nitrogen contents corresponding to alkylene polyamines of theformula H₂N-(A-NH—)_(n)H, where A in this formula is divalent ethyleneor propylene and n is an integer of from 1 to 10, preferably 1 to 4. Thealkylene polyamines may be obtained by the reaction of ammonia anddihalo alkanes, such as dichloro alkanes.

The amine may also be an aliphatic diamine having one primary orsecondary amino group and at least one tertiary amino group in themolecule. Examples of suitable polyamines includeN,N,N″,N″-tetraalkyldialkylenetriamines (two terminal tertiary aminogroups and one central secondary amino group),N,N,N′,N″-tetraalkyltrialkylenetetramines (one terminal tertiary aminogroup, two internal tertiary amino groups and one terminal primary aminogroup), N,N,N′,N″,N′″-pentaalkyltrialkylenetetramines (one terminaltertiary amino group, two internal tertiary amino groups and oneterminal secondary amino group), N,N-dihydroxyalkyl-alpha-,omega-alkylenediamines (one terminal tertiary amino group and oneterminal primary amino group), N,N,N′-trihydroxyalkyl-alpha,omega-alkylenediamines (one terminal tertiary amino group and oneterminal secondary amino group),tris(dialkylaminoalkyl)aminoalkylmethanes (three terminal tertiary aminogroups and one terminal primary amino group), and similar compounds,wherein the alkyl groups are the same or different and typically containno more than about 12 carbon atoms each, and which preferably containfrom 1 to 4 carbon atoms each. These alkyl groups may be methyl and/orethyl groups. Suitable polyamine reactants are N,N-dialkyl-alpha,omega-alkylenediamine, such as those having from 3 to about 6 carbonatoms in the alkylene group and from 1 to about 12 carbon atoms in eachof the alkyl groups, which most preferably are the same but which can bedifferent. Also suitable are N,N-dimethyl-1,3-propanediamine andN-methyl piperazine.

Examples of polyamines having one reactive primary or secondary aminogroup that can participate in the Mannich condensation reaction, and atleast one sterically hindered amino group that cannot participatedirectly in the Mannich condensation reaction to any appreciable extentinclude N-(tert-butyl)-1,3-propanediamine,N-neopentyl-1,3-propanediamine-,N-(tert-butyl)-1-methyl-1,2-ethanediamine,N-(tert-butyl)-1-methyl-1,3-propanediamine, and3,5-di(tert-butyl)aminoethylpiperazine.

Representative aldehydes for use in the preparation of the Mannich baseproducts include the aliphatic aldehydes such as formaldehyde,acetaldehyde, propionaldehyde, butyraldehyde, valeraldehyde,caproaldehyde, heptaldehyde, stearaldehyde. Aromatic aldehydes which maybe used include benzaldehyde and salicylaldehyde. Illustrativeheterocyclic aldehydes for use herein are furfural and thiophenealdehyde, etc. Also useful are formaldehyde-producing reagents such asparaformaldehyde, or aqueous formaldehyde solutions such as formalin.Most preferred is formaldehyde or formalin.

Suitable Mannich base detergents include those detergents taught in U.S.Pat. Nos. 4,231,759; 5,514,190; 5,634,951; 5,697,988; 5,725,612; and5,876,468, the disclosures of which are incorporated herein byreference.

Another suitable additional fuel additive may be hydrocarbyl aminedetergents. If used, the fuel composition may include about 45 to about1000 ppm of the hydrocarbyl amine detergent. One common process involveshalogenation of a long chain aliphatic hydrocarbon such as a polymer ofethylene, propylene, butylene, isobutene, or copolymers such as ethyleneand propylene, butylene and isobutylene, and the like, followed byreaction of the resultant halogenated hydrocarbon with a polyamine. Ifdesired, at least some of the product can be converted into an aminesalt by treatment with an appropriate quantity of an acid. The productsformed by the halogenation route often contain a small amount ofresidual halogen such as chlorine. Another way of producing suitablealiphatic polyamines involves controlled oxidation (e.g., with air or aperoxide) of a polyolefin such as polyisobutene followed by reaction ofthe oxidized polyolefin with a polyamine. For synthesis details forpreparing such aliphatic polyamine detergent/dispersants, see forexample U.S. Pat. Nos. 3,438,757; 3,454,555; 3,485,601; 3,565,804;3,573,010; 3,574,576; 3,671,511; 3,746,520; 3,756,793; 3,844,958;3,852,258; 3,864,098; 3,876,704; 3,884,647; 3,898,056; 3,950,426;3,960,515; 4,022,589; 4,039,300; 4,128,403; 4,166,726; 4,168,242;5,034,471; 5,086,115; 5,112,364; and 5,124,484; and published EuropeanPatent Application 384,086. The disclosures of each of the foregoingdocuments are incorporated herein by reference. The long chainsubstituent(s) of the hydrocarbyl amine detergent most preferablycontain(s) an average of 40 to 350 carbon atoms in the form of alkyl oralkenyl groups (with or without a small residual amount of halogensubstitution). Alkenyl substituents derived from poly-alpha-olefinhomopolymers or copolymers of appropriate molecular weight (e.g.,propene homopolymers, butene homopolymers, C3 and C4 alpha-olefincopolymers, and the like) are suitable. The substituent may be apolyisobutenyl group formed from polyisobutene having a number averagemolecular weight (as determined by gel permeation chromatography) in therange of 500 to 2000, preferably 600 to 1800, most preferably 700 to1600.

Polyetheramines are yet another suitable additional detergent chemistryused in the methods of the present disclosure. If used, the fuelcomposition may include about 45 to about 1000 ppm of the polyetheraminedetergents. The polyether backbone in such detergents can be based onpropylene oxide, ethylene oxide, butylene oxide, or mixtures of these.Propylene oxide or butylene oxide or mixtures thereof may impart goodfuel solubility. The polyetheramines can be monoamines, diamines ortriamines. Examples of commercially available polyetheramines are thoseunder the tradename Jeffamines™ available from Huntsman Chemical companyand the poly(oxyalkylene)carbamates available from Chevron ChemicalCompany. The molecular weight of the polyetheramines will typicallyrange from 500 to 3000. Other suitable polyetheramines are thosecompounds taught in U.S. Pat. Nos. 4,191,537; 4,236,020; 4,288,612;5,089,029; 5,112,364; 5,322,529; 5,514,190 and 5,522,906.

In some approaches, one or more liquid carriers or induction aids may beused. Such carriers can be of various types, such as for example liquidpoly-α-olefin oligomers, mineral oils, liquid poly(oxyalkylene)compounds, liquid alcohols or polyols, polyalkenes, liquid esters, andsimilar liquid carriers. Mixtures of two or more such carriers can beemployed.

Exemplary liquid carriers may include a mineral oil or a blend ofmineral oils that have a viscosity index of less than about 120; one ormore poly-α-olefin oligomers; one or more poly(oxyalkylene) compoundshaving an average molecular weight in the range of about 500 to about3000; polyalkenes; polyalkyl-substituted hydroxyaromatic compounds; ormixtures thereof. The mineral oil carrier fluids that can be usedinclude paraffinic, naphthenic and asphaltic oils, and can be derivedfrom various petroleum crude oils and processed in any suitable manner.For example, the mineral oils may be solvent extracted or hydrotreatedoils. Reclaimed mineral oils can also be used. Hydrotreated oils are themost preferred. Preferably the mineral oil used has a viscosity at 40°C. of less than about 1600 SUS, and more preferably between about 300and 1500 SUS at 40° C. Paraffinic mineral oils most preferably haveviscosities at 40° C. in the range of about 475 SUS to about 700 SUS. Insome instances, the mineral oil may have a viscosity index of less thanabout 100, in other instances, less than about 70 and, in yet furtherinstances, in the range of from about 30 to about 60.

The poly-α-olefins (PAO) suitable for use as carrier fluids are thehydrotreated and unhydrotreated poly-α-olefin oligomers, such as,hydrogenated or unhydrogenated products, primarily trimers, tetramersand pentamers of alpha-olefin monomers, which monomers contain from 6 to12, generally 8 to 12 and most preferably about 10 carbon atoms. Theirsynthesis is outlined in Hydrocarbon Processing, February 1982, page 75et seq., and in U.S. Pat. Nos. 3,763,244; 3,780,128; 4,172,855;4,218,330; and 4,950,822. The usual process essentially comprisescatalytic oligomerization of short chain linear alpha olefins (suitablyobtained by catalytic treatment of ethylene). The poly-α-olefins used ascarriers will usually have a viscosity (measured at 100° C.) in therange of 2 to 20 centistokes (cSt). The poly-α-olefin may have aviscosity of at least 8 cSt, and most preferably about 10 cSt at 100° C.

Suitable poly (oxyalkylene) compounds for the carrier fluids may befuel-soluble compounds which can be represented by the following formula

R_(A)—(R_(B)—O)_(w)—R_(C)

wherein R_(A) is typically a hydrogen, alkoxy, cycloalkoxy, hydroxy,amino, hydrocarbyl (e.g., alkyl, cycloalkyl, aryl, alkylaryl, aralkyl,etc.), amino-substituted hydrocarbyl, or hydroxy-substituted hydrocarbylgroup, R_(B) is an alkylene group having 2 to 10 carbon atoms(preferably 2-4 carbon atoms), R_(C) is typically a hydrogen, alkoxy,cycloalkoxy, hydroxy, amino, hydrocarbyl (e.g., alkyl, cycloalkyl, aryl,alkylaryl, aralkyl, etc.), amino-substituted hydrocarbyl, orhydroxy-substituted hydrocarbyl group, and w is an integer from 1 to 500and preferably in the range of from 3 to 120 representing the number(usually an average number) of repeating alkyleneoxy groups. Incompounds having multiple —R_(B)—O— groups, R_(B) can be the same ordifferent alkylene group and where different, can be arranged randomlyor in blocks. Suitable poly (oxyalkylene) compounds include monoolscomprised of repeating units formed by reacting an alcohol with one ormore alkylene oxides, one alkylene oxide, or propylene oxide or butyleneoxide.

The average molecular weight of the poly (oxyalkylene) compounds used ascarrier fluids may be in the range of from about 500 to about 3000, morepreferably from about 750 to about 2500, and most preferably from aboveabout 1000 to about 2000.

One useful sub-group of poly (oxyalkylene) compounds is comprised of thehydrocarbyl-terminated poly(oxyalkylene) monools such as are referred toin the passage at column 6, line 20 to column 7 line 14 of U.S. Pat. No.4,877,416 and references cited in that passage, said passage and saidreferences being fully incorporated herein by reference.

Another sub-group of poly (oxyalkylene) compounds includes one or amixture of alkylpoly (oxyalkylene)monools which in its undiluted stateis a gasoline-soluble liquid having a viscosity of at least about 70centistokes (cSt) at 40° C. and at least about 13 cSt at 100° C. Ofthese compounds, monools formed by propoxylation of one or a mixture ofalkanols having at least about 8 carbon atoms, or in the range of about10 to about 18 carbon atoms, are suitable.

The poly (oxyalkylene) carriers may have viscosities in their undilutedstate of at least about 60 cSt at 40° C. (in other approaches, at leastabout 70 cSt at 40° C.) and at least about 11 cSt at 100° C. (morepreferably at least about 13 cSt at 100° C.). In addition, the poly(oxyalkylene) compounds used in the practice of this inventionpreferably have viscosities in their undiluted state of no more thanabout 400 cSt at 40° C. and no more than about 50 cSt at 100° C. Inother approaches, their viscosities typically do not exceed about 300cSt at 40° C. and typically do not exceed about 40 cSt at 100° C.

Poly (oxyalkylene) compounds also include poly (oxyalkylene) glycolcompounds and monoether derivatives thereof that satisfy the aboveviscosity requirements and that are comprised of repeating units formedby reacting an alcohol or polyalcohol with an alkylene oxide, such aspropylene oxide and/or butylene oxide with or without use of ethyleneoxide, and especially products in which at least 80 mole % of theoxyalkylene groups in the molecule are derived from 1,2-propylene oxide.Details concerning preparation of such poly(oxyalkylene) compounds arereferred to, for example, in Kirk-Othmer, Encyclopedia of ChemicalTechnology, Third Edition, Volume 18, pages 633-645 (Copyright 1982 byJohn Wiley & Sons), and in references cited therein, the foregoingexcerpt of the Kirk-Othmer encyclopedia and the references cited thereinbeing incorporated herein by reference. U.S. Pat. Nos. 2,425,755;2,425,845; 2,448,664; and 2,457,139 also describe such procedures, andare fully incorporated herein by reference.

The poly (oxyalkylene) compounds, when used, typically will contain asufficient number of branched oxyalkylene units (e.g.,methyldimethyleneoxy units and/or ethyldimethyleneoxy units) to renderthe poly (oxyalkylene) compound gasoline soluble. Suitable poly(oxyalkylene) compounds include those taught in U.S. Pat. Nos.5,514,190; 5,634,951; 5,697,988; 5,725,612; 5,814,111 and 5,873,917, thedisclosures of which are incorporated herein by reference.

The polyalkenes suitable for use as carrier fluids include polypropeneand polybutene. The polyalkenes may have a polydispersity (Mw/Mn) ofless than 4. In one embodiment, the polyalkenes have a polydispersity of1.4 or below. In general, polybutenes have a number average molecularweight (Mn) of about 500 to about 2000, preferably 600 to about 1000, asdetermined by gel permeation chromatography (GPC). Suitable polyalkenesfor use in the present invention are taught in U.S. Pat. No. 6,048,373.

The polyalkyl-substituted hydroxyaromatic compounds suitable for use ascarrier fluid include those compounds known in the art as taught in U.S.Pat. Nos. 3,849,085; 4,231,759; 4,238,628; 5,300,701; 5,755,835 and5,873,917, the disclosures of which are incorporated herein byreference.

Various compounds known for use as oxidation inhibitors can be utilizedin the practice of this invention. These include phenolic antioxidants,amine antioxidants, sulfurized phenolic compounds, and organicphosphites, among others. The antioxidant may be composed predominantlyor entirely of either (1) a hindered phenol antioxidant such as2-tert-butylphenol, 2,6-di-tert-butylphenol, 2,4,6-tri-tert-butylphenol,4-methyl-2,6-di-tert-butylphenol,4,4′-methylenebis(2,6-di-tert-butylphenol), and mixed methylene bridgedpolyalkyl phenols, or (2) an aromatic amine antioxidant such as thecycloalkyl-di-lower alkyl amines, and phenylenediamines, or acombination of one or more such phenolic antioxidants with one or moresuch amine antioxidants. Suitable for use in the practice of thisinvention are tertiary butyl phenols, such as 2,6-di-tert-butylphenol,2,4,6-tri-tert-butylphenol, o-tert-butylphenol, and mixtures thereof.

A wide variety of demulsifiers are available for use in the practice ofthis invention, including, for example, polyoxyalkylene glycols,oxyalkylated phenolic resins, and like materials. Particularly preferredare mixtures of, polyoxyalkylene glycols and oxyalkylated alkylphenolicresins, such as are available commercially from Petrolite Corporationunder the TOLAD trademark. One such proprietary product, identified asTOLAD 9308, is understood to be a mixture of these components dissolvedin a solvent composed of heavy aromatic naphtha and isopropanol. Thisproduct has been found efficacious for use in the compositions of thisinvention. However, other known demulsifiers can be used such as TOLAD286.

A variety of materials are available for use as corrosion inhibitors inthe practice of this invention. Thus, use can be made of dimer andtrimer acids, such as are produced from tall oil fatty acids, oleicacid, linoleic acid, or the like. Products of this type are currentlyavailable from various commercial sources, such as, for example, thedimer and trimer acids sold under the HYSTRENE trademark by the HumkoChemical Division of Witco Chemical Corporation and under the EMPOLtrademark by Henkel Corporation. Another useful type of corrosioninhibitor for use in the practice of this invention are the alkenylsuccinic acid and alkenyl succinic anhydride corrosion inhibitors suchas, for example, tetrapropenylsuccinic acid, tetrapropenylsuccinicanhydride, tetradecenylsuccinic acid, tetradecenylsuccinic anhydride,hexadecenylsuccinic acid, hexadecenylsuccinic anhydride, and the like.Also useful are the half esters of alkenyl succinic acids having 8 to 24carbon atoms in the alkenyl group with alcohols such as the polyglycols.Also useful are the aminosuccinic acids or derivatives thereofrepresented by the formula:

wherein each of R², R³, R⁵ and R⁶ is, independently, a hydrogen atom ora hydrocarbyl group containing 1 to 30 carbon atoms, and wherein each ofR¹ and R⁴ is, independently, a hydrogen atom, a hydrocarbyl groupcontaining 1 to 30 carbon atoms, or an acyl group containing from 1 to30 carbon atoms.

The groups R¹, R², R³, R⁴, R⁵ and R⁶ when in the form of hydrocarbylgroups, can be, for example, alkyl, cycloalkyl or aromatic containinggroups. Preferably R¹, R², R³, R⁴, and R⁵ are hydrogen or the same ordifferent straight-chain or branched-chain hydrocarbon radicalscontaining 1-20 carbon atoms. Most preferably, R¹, R², R³, R⁴, and R⁵are hydrogen atoms. R⁶ when in the form of a hydrocarbyl group ispreferably a straight-chain or branched-chain saturated hydrocarbonradical.

A particular example is a tetralkenyl succinic acid of the above formulawherein R¹, R², R³, R⁴, and R⁵ are hydrogen and R⁶ is a tetrapropenylgroup.

One or more additional optional fuel additives may be also present inthe fuel additive packages or fuel compositions of the disclosedembodiments. For example, the fuel additives may contain conventionalquantities of octane improvers, cold flow improvers (CFPP additive),pour point depressants, solvents, lubricity additives, frictionmodifiers, amine stabilizers, combustion improvers, dispersants, heatstabilizers, conductivity improvers, metal deactivators, carrier fluid,marker dyes, organic nitrate ignition accelerators, cyclomatic manganesetricarbonyl compounds, and the like. Similarly, the fuels may containsuitable amounts of conventional fuel blending components such asmethanol, ethanol, dialkyl ethers, 2-ethylhexanol, and the like.

Post-Installation Methods of Treating Gasoline Particulate Filters

B. Lubricant Additives as Dopants

In other examples, the priming composition contains one or moreadditives not typically used as fuel additives. In some cases, additivesdeveloped for use in engine oil formulations may be used. In someexamples, the additives are used neat as the priming composition. Inother examples, the additives may be solubilized in a base oil to createa lubricant formulation that is used as the priming composition. Alubricant formulation typically is made of lubricant additives and abase oil.

The filtration efficiency of a GPF installed in a newly manufacturedvehicle and exposed to particulate matter produced by the primingcomposition comprising lubricant additives may be quantified by initialmiles and/or engine time, as described above. The GPF treated by themethods may have any of the filtration efficiencies described above.

Additives may include one or more of antioxidants, antiwear agents,boron-containing compounds, detergents, dispersants, friction modifiers,molybdenum-containing components, transition metal-containingcomponents, viscosity index improvers, and other optional additivesadded to an engine oil to form a lubricant formulation.

In some examples, the priming composition includes at least one compoundcontaining a chemical element selected from the group consisting of Ca,Mg, Mo, Zn, P, Ti, Mn, W, Na, and K. In some examples, themetal-containing compounds are introduced by specific additives. It isunderstood that the metallic elements often may be present in ionicform. Alternately, the metallic element may be present in anorganometallic form. Metal-containing compounds contribute to theformation of ash, which can be estimated by testing the lubricantformulation for SASH. In some cases, a base oil may be used tosolubilize the additives in a lubricant formulation.

Both the mass of the ash or the oil SASH value and the chemistry of thelubricant additives are important to ensure correct particulatesubstance accumulation. The SASH value is important as it dictates therate of ash accumulation in the GPF relative to the amount of lubricantformulation additive combusted. The ratio is important since the rate ofash accumulation must be controlled in such a way to be rapid while notadding so much lubricant formulation as to negatively impact combustionin the engine. An example of a SASH amount in the lubricant formulationthat has shown utility is presented in Table 2. To effectivelyaccomplish the ash loading goals and not cause other emissions systemsproblems (e.g., the blocking of the 3-way catalyst system or the foulingof the vehicle oxygen sensors), the chemistry of the lubricantformulation must be carefully controlled. Non-limiting examples ofsuitable fuel and lubricant formulations are presented in Table 1 andTable 2, respectively, which in combination serve as an example of asatisfactorily blended priming composition.

In some cases, the priming composition may also include have a fuel. Theamount of lubricant formulation added to the fuel can be adjusted inorder to achieve the desired filtration efficiency based on the fuelconsumption rate and the distance permitted prior to the certificationtesting. In some examples where the priming composition further includesfuel, the lubricant formulation is present in the fuel in an amount ofno more than 3 wt. % based on the weight of the priming composition. Inother examples, the lubricant formulation is present in the fuel in anamount of no more than 2.5 wt. %, no more than 2.0 wt. %, no more than1.5 wt. %, or no more than 1.0 wt. %, based on the weight of the primingcomposition.

While regulatory trends have precipitated a move to low-ash lubricantformulations, in practicing the methods disclosed herein it may bebeneficial to utilize lubricant formulations having a higherash-producing capability, such as using an older formulation. In someexamples, the lubricant formulation has a SASH value of at least 3%, asmeasured by ASTM D874 (2018). In other examples, the lubricantformulation has a SASH value of at least 3%, at least 3.5%, at least 4%,at least 4.5%, or at least 5%, as measured by ASTM D874 (2018).

The composition and methods disclosed herein may be used withparticulate filter, including particulate filters for diesel engines.

EXAMPLES

The following examples are illustrative, but not limiting, of themethods and compositions of the present disclosure. Other suitablemodifications and adaptations of the variety of conditions andparameters normally encountered in the field, and which are obvious tothose skilled in the art, are within the spirit and scope of thedisclosure. All patents and publications cited herein are fullyincorporated by reference herein in their entirety.

Example 1: Improved Filtration Efficiency Using a Priming Composition

As detailed above, improved methods of improving early GPF filtrationefficiency may include contacting the filter with an exhaust stream froman engine burning a priming composition having fuel doped with alubricant formulation comprising motor oil additives.

In this Example, the fuel employed had the characteristics summarized inTable 1:

TABLE 1 Example Fuel Properties. Properties Unit Results Density kg/m3765.7 Sulfur mg/kg 6.1 Oxygenates % (mass) 4.26 Oxygen % (mass) 0.73Methanol % (mass) 0.13 RVP kPa 48 Unwashed gum mg/100 ml 0.8 Washed gummg/100 ml <0.5 Benzene % (vol) 0.13 Aromatics % (vol) 34.4 Olefins %(vol) 17.2 Distillation IBP ° C. 39.6 10% ° C. 61.9 50% ° C. 107.7 90% °C. 184.3 FBP ° C. 201 Residual ml 97 Residual percentage % (vol) 1.1 RON91.8 Distillation index 608

The fuel was doped with the lubricating composition described in Table2. The amount of the lubricating composition compounded with a packageof inorganic and organic additives was 2 weight percent based on thetotal weight of the lubricant formulation plus fuel.

TABLE 2 Example Lubricant oil properties Properties Unit Results Kv40mm2/s 71.96 Kv100 mm2/s 12.13 CCS-30 mPa · s 5900 TBN 6.76 SAP 0.87 MRV(−35°) 26852 ICP B ppm 50 CA ppm 2120 MG ppm 19 MO ppm 112 P ppm 803 ZNppm 889

A bench-mounted GDI test engine equipped with a GPF was operated usingthe doped fuel, and a comparative bench-mounted GDI test engine equippedwith a GPF was operated using the non-doped fuel. Filtration efficiencywas monitored for 10 hours. As shown in FIG. 1, the filtrationefficiency of the GPF of the doped fuel example (square-shaped datapoints) achieved 95% filtration efficiency in less than 3 hours,compared to the comparative example (diamond-shaped data points) thatrequired 6 hours to achieve 95% filtration efficiency. Thus, in thisExample, the method resulted in dramatically improved early filtrationefficiency.

Other embodiments of the present disclosure will be apparent to thoseskilled in the art from consideration of the specification and practiceof the embodiments disclosed herein. As used throughout thespecification and claims, “a” and/or “an” may refer to one or more thanone. Unless otherwise indicated, all numbers expressing quantities ofingredients, properties such as molecular weight, percent, ratio,reaction conditions, and so forth used in the specification and claimsare to be understood as being modified in all instances by the term“about,” whether or not the term “about” is present. Accordingly, unlessindicated to the contrary, the numerical parameters set forth in thespecification and claims are approximations that may vary depending uponthe desired properties sought to be obtained by the present disclosure.At the very least, and not as an attempt to limit the application of thedoctrine of equivalents to the scope of the claims, each numericalparameter should at least be construed in light of the number ofreported significant digits and by applying ordinary roundingtechniques. Notwithstanding that the numerical ranges and parameterssetting forth the broad scope of the disclosure are approximations, thenumerical values set forth in the specific examples are reported asprecisely as possible. Any numerical value, however, inherently containscertain errors necessarily resulting from the standard deviation foundin their respective testing measurements. It is intended that thespecification and examples be considered as exemplary only, with a truescope and spirit of the disclosure being indicated by the followingclaims.

The foregoing examples are susceptible to considerable variation inpractice. Accordingly, the embodiments are not intended to be limited tothe specific exemplifications set forth hereinabove. Rather, theforegoing embodiments are within the spirit and scope of the appendedclaims, including the equivalents thereof available as a matter of law.

The patentees do not intend to dedicate any disclosed embodiments to thepublic, and to the extent any disclosed modifications or alterations maynot literally fall within the scope of the claims, they are consideredto be part hereof under the doctrine of equivalents.

It is to be understood that each component, compound, substituent orparameter disclosed herein is to be interpreted as being disclosed foruse alone or in combination with one or more of each and every othercomponent, compound, substituent or parameter disclosed herein.

It is also to be understood that each amount/value or range ofamounts/values for each component, compound, substituent or parameterdisclosed herein is to be interpreted as also being disclosed incombination with each amount/value or range of amounts/values disclosedfor any other component(s), compounds(s), substituent(s) or parameter(s)disclosed herein and that any combination of amounts/values or ranges ofamounts/values for two or more component(s), compounds(s),substituent(s) or parameters disclosed herein are thus also disclosed incombination with each other for the purposes of this description.

It is further understood that each range disclosed herein is to beinterpreted as a disclosure of each specific value within the disclosedrange that has the same number of significant digits. Thus, a range offrom 1-4 is to be interpreted as an express disclosure of the values 1,2, 3 and 4.

It is further understood that each lower limit of each range disclosedherein is to be interpreted as disclosed in combination with each upperlimit of each range and each specific value within each range disclosedherein for the same component, compounds, substituent or parameter.Thus, this disclosure to be interpreted as a disclosure of all rangesderived by combining each lower limit of each range with each upperlimit of each range or with each specific value within each range, or bycombining each upper limit of each range with each specific value withineach range.

Furthermore, specific amounts/values of a component, compound,substituent or parameter disclosed in the description or an example isto be interpreted as a disclosure of either a lower or an upper limit ofa range and thus can be combined with any other lower or upper limit ofa range or specific amount/value for the same component, compound,substituent or parameter disclosed elsewhere in the application to forma range for that component, compound, substituent or parameter.

What is claimed is:
 1. A gasoline particulate filter comprising: apre-service gasoline particulate filter comprising pores, wherein thepores are at least partially filled with a particulate substance.
 2. Thegasoline particulate filter of claim 1, wherein the pre-service gasolineparticulate filter provides a filtration efficiency of at least 80%after 100 initial miles.
 3. The gasoline particulate filter of claim 1,wherein the particulate substance comprises at least one of a sootsurrogate substance, an ash surrogate substance, and an aggregateparticulate substance.
 4. The gasoline particulate filter of claim 3,wherein the particulate substance comprises one or more of silicapowder, alumina powder, talc, gypsum, soot, ash, flours, starches, andsalts.
 5. The gasoline particulate filter of claim 1, wherein theparticulate substance is present on the gasoline particulate filter inan amount of at least about 0.5 gram/L.
 6. The gasoline particulatefilter of claim 1, wherein the particulate substance is present on thegasoline particulate filter in an amount up to about 6 grams/L.
 7. Thegasoline particulate filter of claim 1, wherein the particulatesubstance comprises a plurality of particles having a diameter of fromabout 10 nanometers to about 200 micrometers.
 8. A method of pretreatinga gasoline particulate filter, comprising: contacting the gasolineparticulate filter comprising pores with a particulate substance priorto installing the gasoline particulate filter in a vehicle to produce apre-treated gasoline particulate filter, wherein the pores are at leastpartially filled with the particulate substance.
 9. The method of claim8, wherein the particulate substance comprises one or more of asurrogate soot substance, a surrogate ash substance, and an aggregatesurrogate substance.
 10. The method of claim 9, wherein the particulatesubstance comprises one or more of silica powder, alumina powder, talc,gypsum, soot, ash, flours, starches, and salts.
 11. The method of claim8, wherein the particulate substance comprises a plurality of particles,wherein each particle has a diameter from about 10 nanometers to about200 micrometers.
 12. The method of claim 8, wherein the contacting isvia pneumatic conveyance of the particulate substance into the gasolineparticulate filter.
 13. The method of claim 8, wherein the pre-treatedgasoline particulate filter is operable to provide a filtrationefficiency of greater than 80% after 100 initial miles.
 14. A method ofincreasing an initial in-service filtration efficiency of a gasolineparticulate filter, comprising: contacting a newly installed gasolineparticulate filter with an exhaust stream comprising particulate matterderived from a priming composition.
 15. The method of claim 14, whereinthe priming composition comprises a fuel and an organometallic compoundcomprising manganese, and wherein the organometallic compound is presentin the priming composition in an amount effective to provide about 2 toabout 36 milligrams of manganese per liter of priming composition. 16.The method of claim 15, wherein priming composition comprisesmethylcyclopentadienyl manganese tricarbonyl (MMT).
 17. The method ofclaim 14, wherein the priming composition comprises at least onecompound containing a chemical element selected from the groupconsisting of Ca, Mg, Mo, Zn, P, Ti, Mn, W, Na, and K.
 18. The method ofclaim 17, wherein the priming composition further comprises a fuel. 19.The method of claim 14, further comprising measuring a filtrationefficiency of the gasoline particulate filter contacted with the primingcomposition, wherein the filtration efficiency is greater than 80% after100 initial miles.
 20. The method of claim 14, further comprising:treating a fuel tank with the priming composition during originalequipment manufacturing, and adding a fuel to the fuel tank.